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    DNA, Chromosomes and the Genomes

    Genetics punnet square, sex lethal etc

    In sheep the polled condition ( hornless ) is controlled by a single gene locus with two alleles. Heterozygous females are polled but heterozygous males have horns. Suppose two Heterozygous sheep were crossed. Refer to attachment for multiple choice questions. In sheep the polled condition ( hornless ) is controlled by a sing

    Codominance in coat colors of palomino horses

    D1 and D2 are a pair of codominant alleles involved in the inheritance of coat colors in horses. Genotypes homozygous for D1 produces chestnut [reddish], heterozygous genotypes palomino [golden color with lighter shade of mane and tail] and homozygous for D2 cremello [almost white]. a) Determine the probable palomino: non-pal

    Codominant alleles in coat color of guinea pigs

    In guinea pigs yellow coat color is produced by homozygous genotype YY, cream color by heterozygous genotype YW and white by homozygous WW. What would be the genotypic and phenotypic ratio of the progeny of matings between two cream colored pigs?

    Predicting base composition in Aspergillus niger and TMV

    Analysis of base composition from DNA extraction in Aspergillus niger was seen to contain 37% cytosine. Using this data predict the % of adenine. If the same were detected in Tobacco Mosaic Virus [TMV], will it be possible to predict the % of adenine. This job gives reasons.

    Predicting DNA structure

    A double stranded DNA virus has 200,000 base pairs. Determine the number of nucleotides present and the total number of complete spirals. How long will this DNA be?

    DNA length in human beings

    Molecular weight of DNA in an autosome of human beings is 0.5 à? 10 power 12. Determine the number of deoxyribonucleotide pairs in this DNA and calculate the length in both micrometers and inches.

    Amino acids produced using fixed proportions of nucleotide residues

    A solution containing 80% cytosine and 20% uracil was used to make synthetic RNAs. A bacterial cell free system produced proteins using these mRNAs in the following proportions: a) 4 times as many serine as leucine residues. b) 16 times as many serine residues as phenylalanine residues. c) 16 times as many proline resid

    Converting mRNA into polypeptide example

    Convert the following mRNA segments into their polypeptide equivalents; a) 5′ GAAAUGGCAGUUUAC 3′ b) 3′ UUUUCGAGAUGUCAA 5′ c) 5′ AAAACCUAGAACCCA 3′ d) 3′ UGACCAGAUCUACCGAAA 5′

    Amino Acids and Codons

    A certain gene consists of 450 nucleotide pairs. The protein product of the gene consists of 150 amino acid residues. How many codons make the 150 residues?

    Amino acid number prediction following mRNA sequence

    How many different mRNAs would specify the following amino acid sequences - a) met - phe - ser - pro b) ile - arg - phe - leu - ala [use the triplet codon chart to find the number of codons representing the amino acids]

    General formula for calculating length of DNA

    Suppose 25,000 μm is 1 inch. Enumerate a formula to find the length of a DNA molecule in inches a) if the length is known in μm and b) only the number of nucleotide pairs is given.

    Composition of bases in yeast

    DNA of a certain species of yeast has thymidilic acid content of 32.6%. If the A/T ratio is 0.97, what is the composition of deoxyadenylic acid?

    Prediction of DNA strandedness is achieved.

    In one set of Φ X phages the deoxyribonucleotide composition was A = 24.7, T = 32.7, G = 24.1 and C = 18.5. Another set of phages had the following deoxyribonucleotide composition - A = 27.6, T = 27.8, G = 22.3 and C = 22.3. a) Find the A/T, G/C ratio of the 2nd set of phages. b) What is the structure of the phage DNA wit

    Probability in drosophila mutation experiment

    In a mutation experiment in drosophila, 45 mutations were detected amongst 543 males that received 2500 Roentgens (R) and 67 mutations in 649 males that received 4000R. What is the number of progeny expected in 1000 progeny of males exposed to 6000R?

    Predicting triplets in laboratory conditions

    Under laboratory conditions, a synthetic polyribonucleiotide was produced using a mixture of A and G with a relative frequency of 5:1 respectively. How would a scientist predict the relative frequencies in which the triplets are expected to form when the ribonucleotides form in a random linear array? Indicate which amino acid(s)

    Triplet codons and probability

    Find the number of triplet codons feasible from 4 ribonucleotides A, U, G and C containing a) no uracil, b) one or more uracils.

    Complimentary sequence prediction

    A strand of DNA is found to have the sequence 5′ AACGTACGTAC 3′. What is the sequence of the nucleotides on the 3′, 5′ strand? Determine the sequence of the m-RNA template of the given sequence.

    Chromosome number in different body cells

    An animal cell has 46 post-mitotic chromosomes in each of its somatic cells. How many chromosomes should be present in the following cells- a) Mature egg, b) 1st polar body, c) Sperm, d) Spermatid, e) Primary spermatocyte, f) Brain cell, g) Secondary oocyte, h) Spermatogonium.

    Recessive Epistasis: Phenotypes

    A locus in Australian Bearded Dragons is involved in the production of pigment. When heterozygous parents mate, 75% of the progeny are colored and the rest are albino. Another phenotype concerns the specific colors that are expressed such that when two green bearded dragons mate, 2/3 of the progeny are green and the rest are spe

    Chi-square testing

    Cross between pure red tomato and yellow tomato produced all red F1 progeny. From the F2 progeny of 400 plants, 90 were yellow. Hypothesize that a single pair of allele is involved such that Y- = Red and yy = Yellow. Test this hypothesis using Chi square test.

    Epistasis: Fruit Color in Summer Squash

    White fruit color in summer squash is dependent on dominant allele W and colored fruit on recessive allele w. In the presence of ww and a dominant gene G, the color of the fruit is yellow. When G is absent, i.e., when it's gg, then the color is green. What F2 phenotypes and proportions are expected when a white fruit WWGG is cro

    Cross between homozygous squash fruits and expected F2 results

    In squash, disc shaped fruit is dependent on dominant gene D and elongated fruit on recessive allele d. Yellow color is controlled by dominant gene R and green color by recessive allele r. Draw a cross between the homozygous squash fruits and summarize the expected results of F2.

    Prediction of crosses and calculating deviation

    A white albino mouse was crossed with a wild grey colored one. The first generation mice were all grey. In the second generation, there were 198 grey and 72 albino mice. a) What can you hypothesize from these results? b) On the basis of your hypothesis compare the observed results with those expected.

    Crosses in Garden Pea

    Garden pea producing round seeds were crossed with those producing wrinkled seeds. The result was the production of 5474 round seeds and 1850 wrinkled seeds. a) What is the original parental cross? b) Indicate the gamete types c) F1 progeny? d) What result do you expect when F1 is selfed? e) Indicate F1 selfed ga